I have not shot my .308 very much. Funds made sure of that.
A week aog I went out and shot the last 20 odd factory Norma Jaktmatch 155gr cartridges and tried out my starting loads for 155gr Lapua Scenar and Hornady A-max bullets.
The details are here in another TFL thread
A recent thread warning reloaders to check their cases prompted me to do so and I noticed the faint rings near the bottom of the cases.
The first 3 photos are from the cases that were fired as they came from the factory. The next 3 showed cases that I had reloaded once, with light loads (next post).
I am inclined to think that it is some sort of scoring from the bolt and chamber action, largely because the area below that line seems far smoother than the area above, all the way to the neck.
If it is CSH, I'll be disappointed as buying these rounds, shooting them and then using the brass is much cheaper than buying unfired Lapua or Sierra cases and loading them, plus the fact that Norma are supposed to make decent brass...
But what do you think?